Slitherine

Regarding upkeep points: does the strength of the unit make a difference? Does a 1-strength-point infantry unit cost 4 PPs--the same as a fresh 10-strength-point infantry unit?

I try to figure out, based on my production, what kind of surplus I should have. I know you can see that in several places on the charts. But I can never calculate to that number.

upkeep = total upkeep * current strength / 10 (rounded up)